For six days last week, malware known as “malvertising” was reportedly lurking in Yahoo’s advertising network, with the potential for attackers to infect internet users’ computers and hold them for ransom. Security researchers say they notified Yahoo of the malware upon discovering it on Sunday, and the company removed the malicious code immediately.

If you visited the New York Times website last week, you may have been surprised to have your browsing interrupted by one of those scammy “we’re scanning your computer for viruses OH NO YOU HAVE A VIRUS!” ads that overtake your window. Now Microsoft has filed 5 lawsuits in an attempt to fight back against the jerks who may have been responsible for it, and certainly for other ads like it all over the web.